Wireless communication system with selectively sized data transport blocks

ABSTRACT

A wireless transmit receive unit and methods for code division multiple access telecommunications are disclosed that process data in a physical layer and a medium access control (MAC) layer. The physical and MAC layers communicate data between each other via transport channels. The transport channels are associated with logical channels. Logical-channel data for the transport channels is provided in data units having a bit size evenly divisible by an integer N. The respective logical channels associated with a transport channel utilize MAC headers that have a selected modulo N bit size such that there is bit alignment of the MAC headers of all the logical channels associated with a particular transport channel.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/539,901 filed Aug. 12, 2009, which is a continuation of U.S. patentapplication Ser. No. 11/363,809 filed Feb. 28, 2006, now U.S. Pat. No.7,746,833, which is a continuation of U.S. patent application Ser. No.10/888,266 filed Jul. 9, 2004, now U.S. Pat. No. 7,039,030, which is acontinuation of U.S. patent application Ser. No. 09/759,553 filed Jan.12, 2001, now U.S. Pat. No. 6,807,192, which claims the benefit of U.S.Provisional Application No. 60/176,150 filed Jan. 14, 2000, all of whichare incorporated by reference herein as if fully set forth.

FIELD OF INVENTION

The present invention relates to wireless communication systems and, inparticular, the selective sizing of data blocks for wireless transportof data in an efficient manner.

BACKGROUND OF THE INVENTION

Radio interfaces such as those proposed by the 3rd GenerationPartnership Project (3G) use Transport Channels (TrCHs) for transfer ofuser data and signaling between User Equipment (UE), such as a MobileTerminal (MT), and a Base Station (BS) or other device within node of acommunication network. Generically, UEs, MTs and BSs can be referred toas wireless transmit receive units (WTRUs).

In 3G Time Division Duplex (TDD), TrCHs are a composite of one or morephysical channels defined by mutually exclusive physical resources. TrCHdata is transferred in sequential groups of Transport Blocks (TBs)defined as Transport Block Sets (TBSs). Each TBS is transmitted in agiven Transmission Time Interval (TTI). User Equipment (UE) and BaseStation (BS) physical reception of TrCHs require knowledge of TransportBlock (TB) sizes.

For each TrCH, a Transport Format Set (TFS) is specified containingTransport Formats (TFs). Each TF, defines a TBS composed of a specifiednumber of TBs where each TB preferably has the same size within a givenTBS. Thus, a finite number of potential TB sizes are defined withrespect to each TrCH.

Radio Resource Control (RRC) signaling is required between the BS and UEto define the attributes of each established TrCH, including a list ofpotential TB sizes. Signaling over the radio interface introduces systemoverhead, which reduces the physical resources available for user datatransmission. Therefore, it is important to minimize RRC signaling andthe number of potential TrCH TB sizes respectively.

All data transferred by specific TrCHs must fit into the TB sizesspecified for the TFS of a particular TrCH. However, variable size datablocks exist that can not be predicted, for Radio Access Network (RAN)and Core Network (CN) signaling data, as well as Non-Real Time (NRT)user data transmissions.

To allow for the transfer of variable size data blocks, a Radio LinkControl (RLC) provides a segmentation and re-assembly multiplexingfunction and a padding function. The segmentation and re-assemblymultiplexing function reduces the size prior to transmission and is usedwhen the transferred data block is larger than the maximum allowed TBsize. The padding function increases the data block or segmented datablock size by padding with extra bits to fit a TB size.

Segmentation and re-assembly of data over more than one TTI is permittedfor some, but not all, types of data. In 3G, it is not permitted, forexample, for Common Control Channel (CCCH) logical data. Thus, thepayload requirements for a TrCH carrying logical CCCH data areinherently restricted.

The RLC processing results in blocks of data called Protocol Data Units(PDUs). A certain amount of each RLC PDU is required for controlinformation. Using a relatively small RLC PDU results in a lowertransfer data to control information ratio consequently resulting in aless efficient use of radio resources. The RLC padding function is usedwhen the transferred data block is not equal to any of the allowed TBsizes. Likewise, the greater the difference between the transferred datablock size and the next larger allowed TB size results in lowering thetransfer data to used physical resources ratio consequently resulting ina less efficient use of radio resources. Therefore, it is important tomaximize the number of potential TB sizes.

Lowering the number of TB sizes reduces RRC signaling overhead andincreases radio interface efficiency. Increasing the number of TB sizesreduces RLC overhead and increases radio interface efficiency. It istherefore important to make the best use of the specified TB sizes foreach TrCH.

TB sizes are the sum of the RLC PDU size and a Medium Access Control(MAC) header size. The MAC header size is dependent on the class oftraffic, which is indicated by the Logical Channel type. A TargetChannel Type Field (TCTF) is provided in the MAC header to indicate towhich logical channel a TB is assigned. A TrCH can support multiplelogical channel types. This means that the finite number of allowed TBsizes must support several MAC header sizes.

For RAN and CN signaling data and NRT user data, the RLC generates octetaligned (8 bit quantities) PDU sizes. Thus, the RLC PDUs are defined asgroups of a selected number of octets, such that the RLC PDU bit size isalways evenly divided by eight, i.e. the RLC PDU bit size always equals0 modulo 8. This characteristic is maintained even when padding isrequired.

Applicant has recognized that, if MAC header sizes for different LogicalChannel types have mutually exclusive bit offsets, TB sizes can not begenerically used for all transmissions. TB sizes have to be defined forspecific MAC headers and logical channels respectively. This increasessignaling overhead and reduces RLC PDU size options, which results inless efficient use of radio resources.

Specifying octet aligned MAC header sizes as is currently done in some3rd generation systems allows for some sharing of TB sizes betweendifferent Logical Channel types, but also increases MAC signalingoverhead since the MAC header size must be at least 8 bits in suchsituations. In 3rd generation TDD mode, certain TrCH and Logical Channelcombinations have very limited transfer block sizes and increasing MACoverhead should be avoided. Therefore, in TDD, TB size definitions arespecific to Logical Channel specific MAC header bit offsets, and asdescribed, reduce overall radio resource efficiency.

Applicant has recognized that without common MAC header bit offsets, itis not possible for MT down-link and BS up-link transmissions to octetalign received frames in a physical layer since the bit offset is basedon the logical channel type which cannot be known while at the physicallayer. Therefore, TB's have to be transferred to layer 2 for logicalchannel determination before bit shifting can occur. This means thatconsiderable processing overhead is introduced for these TrCH's.Applicant has recognized that with TrCH specific bit aligned MACheaders, bit shifting is known at the physical layer and no additionalprocessing overhead is introduced.

SUMMARY OF THE INVENTION

For wireless communication between WTRUs, such as between UEs and a basestation, a CDMA telecommunication system utilizes a plurality ofprotocol layers including a physical layer and a medium access control(MAC) layer such that the MAC layer provides data to the physical layervia plurality of transport channels (TrCHs). Each transport channel(TrCH) is associated with a set of logical channels for transportinglogical channel data within transport channel data. At least one TrCH isassociated with a set of logical channels having at least two logicalchannels of different types.

The physical layer receives blocks of data for transport such that thetransport blocks (TBs) of data includes a MAC header and logical channeldata for one of the TrCHs. Each TB transports data for a given TrCH suchthat the logical channel data includes data associated with a selectedlogical channel from the set of logical channels associated with thegiven TrCH. Each TB has one of a selected limited finite number of TBbit sizes. The logical channel data for each TB has a bit size evenlydivisible by a selected integer N greater than three (3). N ispreferably eight (8) so that the logical data is in the form of an RLCPDU defined in terms of octets of data bits. Preferably the datamanipulation and formatting is performed by one or more computerprocessors.

The MAC header for each TB includes data identifying the selectedlogical channel and has a bit size such that the MAC header bit sizeplus the logical channel data bit size equals one of the TB bit sizes.The MAC header bit size is fixed for TBs transporting data for the sameTrCH and same selected logical channel, but may be different from theMAC header bit size for TBs transporting data for either a differentTrCH or a different selected logical channel.

Preferably, for TrCHs associated with a set of multiple types of logicalchannels, a fixed MAC header bit size is associated with each logicalchannel within the set of logical channels and is selected such thateach fixed MAC header bit size equals M modulo N where M is an integergreater than 0 and less than N. This results in a MAC header bit offsetof M which is the same for all MAC headers associated with a given TrCH.This allows for a MAC header to be smaller than N in size. Thus, when Nis 8, such as for octet aligned RLC PDUs, a MAC header can be smallerthan one octet of data.

Preferably, each MAC header has a data field for data identifying theselected type of logical channel associated with the logical channeldata. A bit size of that data field is preferably selected to determinethe modulo N bit size of the MAC header, i.e. the MAC header bit offset.A shortest data field bit size is preferably provided for the data fieldof the MAC header of one or more logical channels of the set associatedwith the respective TrCH such that the logical channels designated bythe shortest data field size are collectively more frequently used withthe respective TrCH than any other logical channel within the associateset of logical channels. Alternatively, the shortest data field bit sizemay be associated with the most restricted TrCH logical channelcombination payload requirement.

Preferably, the TrCHs includes a forward access channel (FACH)associated with a set of logical channels including a dedicated trafficchannel (DTCH), a dedicated control channel (DCCH), a shared channelcontrol channel (SHCCH), a common control channel (CCCH) and a commontraffic channel (CTCH), and a random access channel (RACH) associatedwith a set of logical channels including the DTCH, the DCCH, the SHCCHand the CCCH. In such case, each MAC header preferably has a TargetChannel Type Field (TCTF) for data identifying the selected logicalchannel type associated with the transport channel data where a bit sizeof the TCTF field is selected to determine the modulo N bit size M ofthe MAC header. The modulo N bit size M of the MAC header is preferably3 modulo 8 for FACH and 2 modulo 8 for RACH.

The TCTF data field bit size is preferably 3 with respect to FACH MACheaders associated with the CCCH, CTCH, SHCCH and BCCH logical channels.The TCTF data field bit size is preferably 5 with respect to the FACHMAC headers associated with the DCCH and DTCH logical channels. The TCTFdata field bit size is preferably 2 with respect to RACH MAC headersassociated with the CCCH and SHCCH logical channels. The TCTF data fieldbit size is preferably 4 with respect to the RACH MAC headers associatedwith the DCCH and DTCH logical channels.

Where the TrCH bit offset is constant for all logical channel typessupported for a given TrCH, the physical layer can pad the MAC header tooctet align the UE DL and UTRAN UL. No padding indicator is needed in ULor DL since the padding is constant for the TrCH.

Other objects and advantages will be apparent to one of ordinary skillin the art from the following detailed description of a presentlypreferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified illustration of a wireless spread spectrumcommunication system.

FIG. 2 is an illustration of data flowing into a common or sharedchannel.

FIG. 3 is an illustration of data flowing into a FACH channel within aRNC.

FIG. 4 is a schematic diagram illustrating a channel mapping withrespect to a MAC layer and a physical layer in a communication systemaccording to the teaching of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a simplified wireless spread spectrum code divisionmultiple access (CDMA) communication system 18. A node b 26 within thesystem 18 communicates with associated user equipment (UE) 20-24 such asa mobile terminal (MT). The node b 26 has a single site controller (SC)30 associated with either a single base station (BS) 28 (shown inFIG. 1) or multiple base stations. Generically, UEs, MTs and BSs can bereferred to as wireless transmit receive units (WTRUs).

A group of node bs 26, 32, 34 is connected to a radio network controller(RNC) 36. To transfer communications between RNCs 36-40, an interface(IUR) 42 between the RNCs is utilized. Each RNC 36-40 is connected to amobile switching center (MSC) 44 which in turn is connected to the CoreNetwork (CN) 46.

To communicate within the system 18, many types of communicationchannels are used, such as dedicated, shared and common. Dedicatedphysical channels transfer data between a node b 26 and a particular UE20-24. Common and shared channels are used by multiple UEs 20-24 orusers. All of these channels carry a variety of data including traffic,control and signaling data.

Since shared and common channels carry data for different users, data issent using protocol data units (PDUs) or packets. As shown in FIG. 2, toregulate the flow of data from differing sources 48, 50, 52 into achannel 56, a controller 54 is used.

One common channel used for transmitting data to the UEs 20-24 is aforward access channel (FACH) 58. As shown in FIG. 3, the FACH 58originates in a RNC 36 and is sent to a node b 28-34 for wirelesstransmission as a spread spectrum signal to the UEs 20-24. The FACH 58carries several data types from various sources, such as a commoncontrol channel (CCCH), dedicated control and traffic channel (DCCH andDTCH), and a downlink and uplink shared channel (DSCH and USCH) controlsignaling via a shared control logical channel (SHCCH). The FACH 58 alsocarries control signaling out of band and similar data transmitted viathe IUR 42 from other RNCs 38-40, such as CCCH, DCCH and DTCH controldata.

Various controllers are used by the RNC 36 to control the flow of data.A radio link controller (RLC) 64 handles the CCCH. A dedicated mediumaccess controller (MAC-d) 66 handles the DCCH and the DTCH. A sharedmedium access controller (MAC-sh) 68 handles the DSCH, USCH controlsignaling. Controlling the FACH 58 is a common medium access controller(MAC-c) 60.

With reference to FIG. 4, there is illustrated a preferred channelmapping with respect to the MAC layer 70 and the physical layer 72. Thetransport channels (TrCHs) 74 transport data over the physical layer 72to associated physical channels 76. Each of the TrCHs 74 is associatedwith one or more logical channels 78. The TrCHs communicate by usingtransport blocks (TB) which are comprised of a MAC header and associatedlogical channel data in a RLC PDU. The MAC header has logical channelidentification information. Preferably, the RLC PDU is defined by dataoctets, so that the RLC PDU bit size equals 0 modulo 8.

Preferably, the TrCHs 74 include a dedicated channel (DCH), a downlinkshared channel (DSCH), a common packet channel (CPCH), a random accesschannel (RACH), a forward access channel (FACH), a paging channel (PCH)and a broadcast channel (BCH). The associated physical channels includea dedicated physical channel (DPDCH), a physical downlink shared channel(PDSCH), a physical common packet channel (PCPCH), a physical randomaccess channel (PRACH), a secondary common control physical channel(SCCPCH) and a primary common control physical channel (PCCPCH). Othertransport and physical channels may be supported, such as an uplinkshared channel (USCH) with an associated physical uplink shared channel(PUSCH).

The logical channels preferably include a dedicated traffic channel(DTCH), a dedicated control channel (DCCH), a shared control channel(SHCCH), a common control channel (CCCH), a common traffic channel(CTCH), a paging control channel (PCCH) and a broadcast control channel(BCCH).

The preferred association of transport channels with physical andlogical channels is illustrated in FIG. 4. For example, the FACH maytransport data to the SCCPCH from any one of the set of logical channelsincluding the DTCH, the DCCH, the SHCCH, the CCCH, or the CTCH.Similarly, the RACH transports data to the PRACH from any one of the setof logical channels including the DTCH, the DCCH, the SHCCH, or theCCCH.

In order to make efficient use of TBS size definitions, it is desirableto be able to use all specified TB sizes for all Logical Channel typessupported by a respective TrCH. This allows the number of specified TFsfor a TFS to be minimized thereby reducing signaling overhead, whilemaximizing the number of RLC PDU size options reducing the overheadassociated with RLC segmentation and padding. TB and TBS assignment isaccomplished without increasing MAC header sizes for TrCH logicalchannel combinations that support limited TB data payloads, i.e. theamount of data processed as a single unit from higher layers within MACand RLC.

A bit aligned MAC header resolves both the radio resource efficiencyissues associated with TB size signaling and RLC segmentation andpadding overhead. The alignment is performed by maintaining the minimumsize MAC headers for the Logical Channel and TrCH combinations thatsupport limited TB data payload sizes, and increasing MAC headers fornon- data payload size sensitive combinations to the same bit offset.

For example, if the data payload size limited combinations have MACheaders of X octets (total octets)+Y bit (extra bit offset, less than 8)sizes, and non-limited combination have headers of A octets+C bits and Boctets+D bits. Then the C and D bits are adjusted to match Y bits. Insome cases this means A and/or B octets must be incremented by oneoctet. It is not necessary for A and B octet sizes to match the X octetsize since TB size=MAC header+RLC PDU and the octet aligned RLC PDU willconform to the available octet size. MAC headers less than an octet inlength are permitted, and in fact desirable, in such cases X, A or B maybe 0.

All TB sizes specified by RRC signaling for a specific TrCH channel willhave a Y bit offset. That Y bit offset being applicable to the MACheaders for all Logical Channels supported by the specific TrCH. Sincethe MAC header octet sizes do not necessarily match between differentLogical Channel types, RLC entities will correspondingly generateappropriate RLC PDU sizes to conform to the allowed TB sizes. This doesnot necessarily mean RLC PDU's have to be resized when switching betweenTrCH types, since it is always possible to adjust the difference in MACheader size between the new and old TrCH's in the allowed TB sizes.

With bit aligned MAC headers, each TrCH type may have a different bitaligned TB size offset. The offset is preferably defined by the mostlimited Logical Channel and TrCH combination block size, which isspecific to the TrCH type. Therefore, each TrCH type has an independentoptimized MAC header bit offset.

The invention has the additional benefit of removing processor intensivelayer 2 bit shifting requirements in the WTRUs, such as the UE and BSequipment. With a common TB size bit offset for all Logical Channelstypes supported by a specific TrCH, it is possible for received radiotransmissions to be bit shifted by the physical layer according tohigher layer requirements. It is advantageous to provide bit shifting atthe physical layer which is already involved in bit manipulationswithout adding additional overhead, as opposed to adding thisrequirement to the higher layer processing requirements.

In 3G system design, RLC and Radio Resource Control (RRC) entitiesgenerate and expect to receive data blocks which start on octetboundaries. If MAC headers for specific TrCH's have variable bit offsetsit is only possible to avoid bit shifting in BS down-link and MT up-linktransmissions. In the MT down-link and BS up-link cases it is notpossible for the physical layer to be aware of the higher layer logicalchannel type that defines the bit offset. Only if the bit offset iscommon for all transmissions across the specific transport channel canbit processing be avoided in communication layers 2 and 3.

RRC Transport Format Set (TFS) signaling is used to define TransportBlock (TB) sizes for each defined Transport Format (TF) allowed on aspecific TrCH. The number of possible TB sizes should be minimized toreduce the signaling load. It is also necessary to choose TB sizeswisely since RLC PDU padding can dramatically increase transmissionoverhead.

Preferably, there is a maximum of 32 possible TB sizes in each TrCH'sTFS. Specifying all 32 results in a significant signaling load thatshould be avoided. Although it is also important to have as many choicesas possible on transport channels which have variable transmissionssince RLC Acknowledged Mode (AM) and Unacknowledged Mode (UM) PDU's willbe padded to match the next larger TB size when the previous lower sizeis exceeded.

The relation between RLC PDU and TB sizes is as follows: TB Size=MACHeader Size+RLC PDU Size.

In the preferred RLC AM and UM, the PDU size is always octet aligned andin Time Division Duplex (TDD) a variable non-octet aligned MAC headerexists. Therefore, MAC individual bit offsets must be taken into accountwhen specifying the allowed TB sizes.

In TDD, with the exception of DTCH/DCCH all logical channel combinationson the FACH and separately on the RACH are modified from the prior artto have the same bit offset (+2 bits for RACH and +3 bits for FACH whenmultiple logical channels are allowed). Table 1 reflects a preferredprior art MAC header size specification.

With the prior art MAC header definitions, octet aligned AM and UM RLCpayloads will result in two possible TB size bit offsets on RACH andFACH when multiple logical channel types are applied. Octet +1 or 3 bitsfor FACH and octet +0 or 2 bits for RACH. This potentially doubles thenumber of Transport Formats that need to be specified on RACH and FACH.

TABLE 1 Prior Art TDD RACH/FACH MAC Header Sizes by Logical Channel TypeUE-id UE- C/T Header Logical CH TrCH TCTF Field Type id Field SizeDCCH/DTCH FACH 3 2 16/32 4 25/41 CCCH FACH 3 N/A N/A N/A 3 CTCH FACH 3N/A N/A N/A 3 SHCCH FACH 0/3 (Note 1) N/A N/A N/A 0/3 BCCH FACH 3 N/AN/A N/A 3 DCCH/DTCH RACH 2 2 16 4 24  CCCH RACH 2 N/A N/A N/A 2 SHCCHRACH 0/2 (Note 1) N/A N/A N/A 0/2 (Note 1): SHCCH does not require TCTFwhen SHCCH is the only channel assigned to RACH or FACH.

To increase the efficiency of TFS signaling and allow for more RLC PDUsize choices, it is necessary to have a common TB size bit offset.Increasing MAC header sizes for CCCH, SHCCH, CTCH and BCCH, should beavoided since these channels operate in RLC TM where RLC segmentationacross multiple radio frame TTIs is not possible. Therefore, thepreferred solution is to increase the DCCH/DTCH TCTF by 2 bits on RACHand FACH. A preferred coding is reflected in Tables 2 and 3 below,respectively for FACH and RACH. This results in common RACH TB sizes ofoctet+2, i.e. 2 modulo 8, and FACH TB sizes of octet+3, i.e. 3 modulo 8.

Another benefit of MAC header bit alignment is the ability to remove theUE and RNC layer 2 bit shifting requirement. The RLC generates andexpects to receive octet aligned PDU's. With variable bit shifted MACheaders only the UTRAN Down Link (DL) and UE Up Link (UL) MAC PDU'scould avoid layer 2 bit shifting by padding the MAC header and providinga padding indicator to the physical layer. This is not possible for theUE DL and UTRAN UL transmissions since physical layer is unaware of thelogical channel type on RACH and FACH.

If the TrCH bit offset is constant for all logical channel typessupported for a given TrCH, the physical layer can pad the MAC header tooctet align the UE DL and UTRAN UL. No padding indicator is needed in ULor DL since the padding is constant for the TrCH. For example, apresently preferred embodiment described above has common RACH TB sizesof octet+2, i.e. 2 modulo 8, and FACH TB sizes of octet+3, i.e. 3 modulo8. Thus it necessarily follows that TB padding of 6 bits for all RACHlogical channels and TB padding of 5 bits for all FACH logical channelsresults in octet alignment for UL and DL transmissions with respect tothe embodiment of the invention described above.

The number of TFs specifying TB sizes allowed in each TFS on a specificTrCH should be minimized to reduce the layer 3 signaling load. It isalso necessary to allow a maximum number of octet aligned RLC PDU sizesin AM and UM for efficient transfer of DCCH/DTCH data. In TDD mode bitshifted MAC headers potentially doubles the number of TFs that need tobe defined on RACH and FACH TrCHs. Additionally, variable bit shiftedMAC headers result in requiring layer 2 bit shifting for all UE DL andUTRAN UL transmissions on RACH and FACH. MAC header bit alignment isdefined to avoid duplication of TB size definitions for octet alignedRLC PDUs and layer 2 bit shifting.

As in the prior art, the MAC header preferably includes a Target ChannelType Field (TCTF). The TCTF field is a flag that provides identificationof the logical channel type on FACH and RACH transport channels, i.e.whether it carries BCCH, CCCH, CTCH, SHCCH or dedicated logical channelinformation. Unlike the prior art, the preferred size and coding of TCTFfor TDD are shown in Tables 2 and 3.

TABLE 2 Coding of the Target Channel Type Field on FACH for TDD TCTFDesignation   000 BCCH   001 CCCH   010 CTCH 01100 DCCH or DTCH OverFACH 01101-01111 Reserved (PDUs with this coding will be discarded bythis version of the protocol)   100 SHCCH 101-111 Reserved (PDUs withthis coding will be discarded by this version of the protocol)

TABLE 3 Coding of the Target Channel Type Field on RACH for TDD TCTFDesignation   00 CCCH 0100 DCCH or DTCH Over RACH 0101-0111 Reserved(PDUs with this coding will be discarded by this version of theprotocol)   10 SHCCH   11 Reserved (PDUs with this coding will bediscarded by this version of the protocol)

Note that the preferred size of the TCTF field of FACH for TDD is either3 or 5 bits depending on the value of the 3 most significant bits. Thepreferred TCTF of the RACH for TDD is either 2 or 4 bits depending onthe value of the 2 most significant bits.

Bit aligned MAC headers allow common TB sizes to be defined fordifferent logical channels on the same TrCH. Common TB sizes reducesignaling overhead and potentially increase the options for RLC PDUsizes, which increases system efficiency by reducing the need forpadding in AM and UM.

This is especially important for RACH and FACH channels where a commonTrCH supports many different traffic types. Optimally for RACH and FACH,each TB size specified can apply to DCCH, CCCH, CTCH, SHCCH and DTCH. Toallow this capability in octet mode it is preferred to specify the totalnumber of octets not just the number of RLC PDU octets.

By specifying the total number of octets, it is not necessary toindicate the TDD MAC header type on common channels since the headeroffset is the same for all logical channel types. It is also possible toavoid RLC PDU resizing transport channel switching by taking intoaccount the change in MAC header octet offset.

Table 4 is a preferred specification for a Transport Format Set (TFS) ina 3G system.

TABLE 4 Transport Format Set (TFS) Information Element/ Type andSemantics Group name Need Multi reference description CHOICE MPTransport channel type >Dedicated The transport transport channel thatis channels configured with this TFS is of type DCH >>Dynamic MP 1 toNote 1 Transport For- <maxTF> mat Inform- ation >>>RLC Size MP IntegerUnit is bits (0..4992) Note 2 >>>Number of MP 1 to Present for every TBsand TTI <maxTF> valid number of List TB's (and TTI) for this RLCSize. >>>>Trans- CV- Integer Unit is ms. mission Time dynam- (10, 20,Interval ic TTI 40, 80) >>>>Number MP Integer Note 3 of Transport(0..512) blocks >Common The transport transport channel that is channelsconfigured with this TFS is of a type not equal to DCH >>Dynamic MP 1 toNote Transport For- <maxTF> mat Inform- ation >>>RLC Size MP IntegerUnit is bits (0..4992) Note 2 >>>Number MP 1 to Present for every of TBsand <maxTF> valid number of TTI List TB's (and TTI) for this RLCSize. >>>>Number MP Integer Note 3 of Transport (0..512)blocks >>>>CHOICE MP mode >>>>>FDD (no data) >>>>>TDD >>>>>Trans- CV-Integer Unit is ms. mission Time dynam- (10, 20, Interval ic TTI 40,80) >>>CHOICE MP The logical Logical Chan- channels that are nel Listallowed to use This RLC Size >>>>ALL Null All logical channels mapped tothis transport channel. >>>>Con- Null The logical chan- figured nelsconfigured to use this RLC size in the RB mapping info. 10.3.4.21 ifpresent in this message or in the previously stored configurationotherwise >>>>Explicit 1 to 15 Lists the logical List channels that areallowed to use this RLC size. >>>>>RB MP RB Identity identity10.3.4.16 >>>>>Logical CV- Integer Indicates the rele- Channel UL-(0..1) vant UL logical RLC channel for this Log- RB. “0” corre- icalsponds to the first, Chan- “1” corresponds nels to the second UL logicalchannel configured for this RB in the IE “RB mapping >>Semi-static MPSemi- info”. Transport static Format Inform- Trans- ation port FormatInform- ation 10.3.5.11 Condition Explanation DynamicTTI This IE isincluded if dynamic TTI usage is indicated in IE Transmission TimeInterval in Semi-static Transport Format Information. Otherwise it isnot needed. UL-RLCLogicalChannels If “Number of uplink RLC logicalchannels” in IE “RB mapping info” in this message is 2 or the IE “RBmapping info” is not present in this message and 2 UL logical channelsare configured for this RB, then this IE is present. Otherwise this IEis not needed. NOTE: The parameter “rate matching attribute” is in linewith the RAN WG1 specifications. However, it is not currently in linewith the description in 25.302. NOTE 1: The first instance of theparameter Number of TBs and TTI List within the Dynamic transport formatinformation correspond to transport format 0 for this transport channel,the second to transport format 1 and so on. The total number ofconfigured transport formats for each transport channel does not exceed<maxTF>. NOTE 2: For dedicated channels, ‘RLC size’ reflects RLC PDUsize. In FDD for common channels ‘RLC size’ reflects actual TB size. InTDD for common channels since MAC headers are not octet aligned, tocalculate TB size the MAC header bit offset is added to the specifiedsize (similar to the dedicated case). Therefore for TDD DCH TrCHs the 4bit C/T is added if MAC multiplexing is applied, for FACH the 3 bit TCTFoffset is added and for RACH the 2 bit TCTF offset is added. NOTE 3: Ifthe number of transport blocks < > 0, and Optional IE “CHOICE RLC mode”or “CHOICE Transport block size is absent, it implies that no RLC PDUdata exists but only parity bits exist. If the number of transportblocks = 0, it implies that neither RLC PDU data nor parity bits exist.In order to ensure the possibility of CRC based Blind Transport FormatDetection, UTRAN should configure a transport format with number oftransport block < > 0, with a zero-size transport block.

In summary, the invention provides an improvement to a CDMAtelecommunication system that has a physical layer and a MAC layer, withthe MAC layer providing data to the physical layer via a plurality oftransport channels utilizing data transfer blocks of specific sizes foreach channel, with each transport channel associated with a set oflogical channels where for at least one transfer channel the set oflogical channels has at least two logical channels with differentlogical types. One implementation of the invention is preferably in theform of a processor for associating, for a given transport channelassociated with a logical channel set having two (2) different types oflogical channels, a fixed MAC header bit size with each logical channelwithin the set with each fixed MAC header bit size equal M modulo Nwhere N is a selected integer greater than three (3) and M is an integergreater than zero (0) and less than N. The processor is configured toselect a logical channel having logical-channel data for transport froma set of logical channels associated with the given transport channel,with the logical-channel data for each transport block having a bit sizeevenly divisible N. The processor also provides the logical-channel datafrom the MAC layer to the physical layer via the given transport channelas a plurality of transport-blocks of data, with each transport block ofdata including a MAC header and logical-channel data for the transportgiven channel, with each transport block of data having one of a finitenumber of transport block (TB) bit sizes, with a first bit size of afirst MAC header set to a first fixed size for transport blockstransporting data for the same transport channel and same selectedlogical-channel data, with the first bit size of the MAC header plus thefirst bit size of the logical-channel data equal to one of the TB bitsizes, and with a second bit size of a second MAC header set to a secondfixed size for transport blocks transporting data for a differenttransport channel or different selected logical-channel data, with thesecond bit size of the MAC header plus the second bit size of thedifferent logical-channel data equal to one of the TB bit sizes.

REFERENCES

3GPP TSG-RAN Working Group 2 Meeting #10, Tdoc R2-00-057

3GPP TSG-RAN Working Group 2 Meeting #10, Tdoc R2-00-060

The following is a listing of acronyms and their meanings as usedherein:

AM Acknowledged Mode BCCH Broadcast Control Channel BCH BroadcastChannel BS Base Station CCCH Common Control Channel CDMA Code DivisionMultiple Access CN Core Network CPCH Common Packet Channel CTCH CommonTraffic Channel DCCH Dedicated Control Channel DCH Dedicated Channel DLDown Link DPDCH Dedicated Physical Channel DPSCH Physical DownlinkShared Channel DSCH Downlink Shared Channel DTCH Dedicated TrafficChannel FACH Forward Access Channel MAC Medium Access Control MAC-cCommon Medium Access Control MAC-d Dedicated Medium Access ControlMAC-sh Shared Medium Access Control MSC Mobile Switching Center MTMobile Terminal NRT Non-Real Time PCCPCH Primary Common Control PhysicalChannel PCH Paging Channel PCPCH Physical Common Packet Channel PDUProtocol Data Units PRACH Physical Random Access Channel PUSCH PhysicalUplink Shared Channel RACH Random Access Channel RAN Radio AccessNetwork RLC Radio Link Control RNC Radio Network Controller RRC RadioResource Control SC Site Controller SCCPCH Secondary Common ControlPhysical Channel SHCCH Shared Channel Control Channel TB Transport BlockTCTF Target Channel Type Field TDD Time Division Duplex TF TransportFormat TFS Transport Format Set TrCH Transport Channel UE User EquipmentUL Up Link UM Unacknowledged Mode USCH Uplink Shared Channel WTRUWireless Transmit Receive Unit

1. A wireless transmit receive unit (WTRU) for code division multipleaccess (CDMA) telecommunications comprising: a processor configured toprocess data in a physical layer and a medium access control (MAC) layersuch that the MAC layer communicates data with the physical layer via aplurality of transport channels, where one transport channel is a randomaccess channel (RACH) associated with a set of logical channelsincluding: at least one of a dedicated traffic channel (DTCH) and adedicated control channel (DCCH), and at least one of a shared channelcontrol channel (SHCCH) and a common control channel (CCCH); saidprocessor configured to process logical-channel data for the RACH indata units having a bit size evenly divisible by N where N is an integergreater than three; and said processor configured to processlogical-channel data for each logical channel within said set of logicalchannels associated with the RACH with a RACH MAC header that has aselected bit size equal to M_(r) modulo N bits.
 2. The WTRU according toclaim 1 wherein said processor is configured to process a RACH MACheader with each logical channel associated with the RACH where eachrespective MAC header has a Target Channel Type Field (TCTF) for dataidentifying a type of logical channel associated with the logicalchannel data.
 3. The WTRU according to claim 2 wherein said processor isconfigured to process a RACH MAC header having a TCTF bit size of fourbits for RACH MAC headers of the dedicated traffic channel (DTCH) andthe dedicated control channel (DCCH) and a TCTF bit size of two bits forRACH MAC headers of the shared channel control channel (SHCCH) and thecommon control channel (CCCH).
 4. The WTRU according to claim 3 wherein:said processor is configured to process a RACH MAC header for: the RACHDTCH having a TCTF coded with bits 0100; the RACH DCCH having a TCTFcoded with bits 0100; the RACH SHCCH having a TCTF coded with bits 10;and the RACH CCCH having a TCTF coded with bits
 00. 5. The WTRUaccording to claim 4 wherein said processor is configured to processlogical-channel data for the RACH where N equals eight in the form ofdata units made up of data octets and to process RACH MAC headers havinga bit size of two modulo eight bits with each logical channel associatedwith the RACH.
 6. The WTRU according to claim 1 wherein said processoris configured to process logical-channel data for the RACH where Nequals eight in the form of data units made up of data octets and toprocess RACH MAC headers having a bit size of two modulo eight bits witheach logical channel associated with the RACH.
 7. The WTRU according toclaim 1 wherein said processor is configured to process data fortransmission by associating a MAC header with respective RACH logicalchannels to provide the data from the MAC layer to the physical layer.8. The WTRU according to claim 1 configured as a user equipment or abase station.
 9. A wireless transmit receive unit (WTRU) for codedivision multiple access (CDMA) telecommunications comprising: aprocessor configured to process data in a physical layer and a mediumaccess control (MAC) layer such that the MAC layer communicates datawith the physical layer via a plurality of transport channels, where onetransport channel is a Time Division Duplex (TDD) random access channel(RACH) associated with a set of logical channels including: at least oneof a dedicated traffic channel (DTCH) and a dedicated control channel(DCCH), and at least one of a shared channel control channel (SHCCH) anda common control channel (CCCH); and said processor configured toassociate a RACH MAC header having a selected bit size with each logicalchannel within said set of logical channels associated with the RACHwhere each RACH MAC header has a Target Channel Type Field (TCTF) fordata identifying a type of logical channel associated with the logicalchannel data such that the RACH MAC header TCFTs for the dedicatedtraffic channel (DTCH) and the dedicated control channel (DCCH) have abit size of four bits and the RACH MAC header TCFTs for the sharedchannel control channel (SHCCH) and the common control channel (CCCH)have a TCTF bit size of two bits.
 10. The WTRU according to claim 9wherein: said processor is configured to associate a RACH MAC headerfor: the RACH DTCH having a TCTF coded with bits 0100; the RACH DCCHhaving a TCTF coded with bits 0100; the RACH SHCCH having a TCTF codedwith bits 10; and the RACH CCCH having a TCTF coded with bits
 00. 11.The WTRU according to claim 9 wherein: said processor is configured toprocess logical-channel data for the RACH in data units comprised ofdata octets; and said processor is configured to provide logical-channeldata for the RACH from the MAC layer to the physical layer as transportblocks of data, such that each transport block of data that includes aRACH MAC header and logical-channel data for the RACH has one of afinite number of transport block (TB) bit sizes where the transportblock bit sizes are each of a size equal to two modulo eight bits. 12.The WTRU according to claim 11 wherein: said processor is configured toassociate a RACH MAC header for: the RACH DTCH having a TCTF coded withbits 0100; the RACH DCCH having a TCTF coded with bits 0100; the RACHSHCCH having a TCTF coded with bits 10; and the RACH CCCH having a TCTFcoded with bits
 00. 13. The WTRU according to claim 9 wherein saidprocessor is configured to process data for transmission by associatinga MAC header with respective RACH logical channels to provide the datafrom the MAC layer to the physical layer.
 14. The WTRU according toclaim 9 configured as a user equipment or a base station.
 15. A wirelesstransmit receive unit (WTRU) for code division multiple access (CDMA)telecommunications comprising: a processor configured to process data ina physical layer and a medium access control (MAC) layer such that theMAC layer communicates data with the physical layer via a plurality oftransport channels, where one transport channel is a Time DivisionDuplex (TDD) random access channel (RACH) associated with a set oflogical channels including a dedicated traffic channel (DTCH), adedicated control channel (DCCH), a shared channel control channel(SHCCH) and a common control channel (CCCH); said processor configuredto process a MAC header with respective RACH logical channels where eachMAC header has a Target Channel Type Field (TCTF); and said processorconfigured to process a MAC header for: the RACH DTCH having a TCTFcoded with bits 0100; the RACH DCCH having a TCTF coded with bits 0100;the RACH SHCCH having a TCTF coded with bits 10; and the RACH CCCHhaving a TCTF coded with bits
 00. 16. The WTRU according to claim 15wherein said processor is configured to process data for transmission byassociating a MAC header with respective RACH logical channels toprovide the data from the MAC layer to the physical layer.
 17. The WTRUaccording to claim 15 configured as a user equipment or a base station.18. A method for code division multiple access (CDMA) telecommunicationscomprising: providing a wireless transmit receive unit (WTRU) having aphysical layer and a medium access control (MAC) layer configured suchthat the MAC layer communicates data with the physical layer via aplurality of transport channels, where one transport channel is a randomaccess channel (RACH) associated with a set of logical channelsincluding: at least one of a dedicated traffic channel (DTCH) and adedicated control channel (DCCH), and at least one of a shared channelcontrol channel (SHCCH) and a common control channel (CCCH); processinglogical-channel data for the RACH in data units having a bit size evenlydivisible by N where N is an integer greater than three; and processinglogical-channel data for logical channels associated with the RACH withRACH MAC headers where each RACH MAC header has a bit size equal toM_(r) modulo N bits.
 19. The method according to claim 18 wherein theprocessing of respective MAC headers with logical channels associatedwith the RACH includes providing a Target Channel Type Field (TCTF) fordata identifying a type of logical channel associated with the logicalchannel data in each respective MAC header.
 20. The method according toclaim 19 wherein: a RACH MAC header having a TCTF bit size of four bitsis used for RACH MAC headers of the dedicated traffic channel (DTCH) andthe dedicated control channel (DCCH); and a RACH MAC header having aTCTF bit size of two bits is used for RACH MAC headers of the sharedchannel control channel (SHCCH) and the common control channel (CCCH).21. The method according to claim 20 wherein: a RACH MAC header for: theRACH DTCH having a TCTF coded with bits 0100 is used; the RACH DCCHhaving a TCTF coded with bits 0100 is used; the RACH SHCCH having a TCTFcoded with bits 10 is used; and the RACH CCCH having a TCTF coded withbits 00 is used.
 22. The method according to claim 21 whereinlogical-channel data for the RACH is processed in the form of data unitsmade up of data octets whereby N equals eight and wherein RACH MACheaders having a bit size of two modulo eight bits are used with eachlogical channel associated with the RACH.